In the liquid crystal module with a small size, a backlight source (BLU) is generally fixed to a display panel using a cell tape.
One side of the display panel is generally provided with a circuit board. The circuit board includes a drive IC, an printed circuit board (PCBA) and a flexible circuit board (FPC) connecting the drive IC to the printed circuit board. The drive IC is bonded to the display panel.
When the backlight source and the display panel are assembled, the display panel and the backlight are buckled together firstly, and the flexible circuit board on the display panel is folded to a back of the display panel to be fixed onto a back plate of the backlight source. Then, the cell tape is used to fully attach four edges of a polarized light sheet (POL) at a front surface of the display panel, and it is folded to the back plate of the backlight source at a back surface of the display panel, wherein at a side of the display panel that has a circuit board, the cell tape overlaps with the circuit board after being folded so as to be attached to the circuit board. The cell tape may function to fix the display panel and the backlight source in one aspect, and may function to protect all the circuit components in another aspect.
Due to differences between the attaching accuracy and the dimensional tolerance and differences between the attaching accuracy and the material property, the cell tape and the circuit board cannot well overlap during a folding process. If the cell tape is attached too tightly, it will apply a pressure that is pulled to a back surface of the display panel to the flexible circuit board, and then, the flexible plate will pull the drive IC so that the display panel is locally deformed due to stress so as to cause an light leakage. The light leakage is particularly apparent against a full-black screen, and it is commonly known as LO light leakage.